M23

M23: Internal derangement of knee

Non-billable headerICD-10-CM

M23 is a non-billable header ICD-10-CM code for internal derangement of knee. It cannot be billed on its own: choose one of the more specific child codes below.

Excludes1: never code together

These conditions cannot occur together. Billing both on the same encounter is a denial.

ankylosis (M24.66)
deformity of knee (M21.-)
osteochondritis dissecans (M93.2)

Excludes2: not included here, but may coexist

The excluded condition is not part of this code, but a patient can have both. You may code both.

current injury - see injury of knee and lower leg (S80-S89)
recurrent dislocation or subluxation of joints (M24.4)
recurrent dislocation or subluxation of patella (M22.0-M22.1)

Other codes that can never be billed with M23

Their own Excludes1 notes name this code, so the conflict is not listed above.

S83.2Tear of meniscus, current injury

Risk adjustment

No CMS-HCC V28 category: this code does not change a RAF score.

Code history

Unchanged in every release from FY2024 to FY2027.

Code to one of these instead M23

8 child codes. Green means billable.